The methanol and downstream products discussion forum is seeking accident cases. Let’s talk more.

I have also been thinking about this issue recently; I would like to share some of my views for everyone’s discussion. We work in the methanol production process using coke oven gas, and we often hear about explosions and burns in the conversion furnaces; I have experienced such incidents myself several times. Here are the reasons I’ve identified: 1. Design issues; for example, the steam control valves in the oxygen inlet pipelines are designed as air-actuated valves, and without instrument air, there is no protection for the steam, which leads to explosions in the oxygen pipelines when cutting off oxygen supply. There are also considerations such as whether the chain setup and actions are reasonable, etc. 2. Equipment issues: The quality of some pouring materials is substandard, which leads to collapse and blockage of the gas pathways, resulting in overheating and explosions. In some cases, the vent valve at the end of the conversion process freezes in winter and cannot be opened, resulting in pressure buildup in the system and ultimately an explosion in the oxygen pipeline. In some steam systems, the reset pressure of the safety valves is low; as a result, the steam pressure drops significantly after the valves activate, leading to explosions in the oxygen pipelines. Among other reasons: 3. Inaccurate instruments, as well as insufficient quality of the materials used for temperature measurement sleeves; the most typical example is the temperature sensing element sleeves in conversion furnaces, and this has been discussed in forums. 4. Most importantly, the operators lack the necessary skills and have little experience. For example, an excessive water-to-carbon ratio can cause shutdown and lead to explosions; the oxygen cutting speed is too slow, decisions are not made promptly, the amount of oxygen supplied to the converter cannot be adjusted properly, and it is not possible to make predictions in advance, among other issues. To operate safely, one must stay vigilant and be meticulous in their work. The above are some humble opinions on the operation of conversion furnaces. In actual production, it is also necessary to pay attention to adjusting various parameters, focusing mainly on protecting the catalyst and following standard procedures in order to extend its service life as much as possible.

The second floor contains the summaries prepared by Yangzijiang himself; I think they are excellent, so I’ve posted them here. I hope everyone will engage in active discussions! Any of the different work sections will do; I hope everyone can use them as a reference in their work.

Company name: Anhui Huaihua Group Company; Process route: Coal gasification (Texaco); Time of incident: December 2002; Consequences of the accident: 3 deaths; Cause of the accident: When China National Chemical Engineering Corporation No. 3 was carrying out construction work to install boilers at Anhui Huaihua Group Company’s thermal power plant, the opening of valves in the nitrogen pipeline allowed a large amount of nitrogen to enter the coal powder silo, resulting in 2 deaths. During the rescue efforts, 1 rescuer died from asphyxiation, resulting in a total of 3 deaths. Pingyin Luxi Chemical Industry’s Third Fertilizer Factory: gasification process; March 2005 – 4 deaths and 32 injuries, with economic losses of around 7.8 million yuan. The cause of the accident was the poor quality of the urea synthesis towers manufactured by the Chemical Machinery Factory of Sinopec Nanjing Chemical Industry Company (both in terms of manufacturing and maintenance), which led to an explosion and subsequent heavy casualties and property damage. Shaanxi Shenmu Chemical Industry Co., Ltd.: gasification process (Texaco); January 2006 – a minor mechanical accident involving a flash explosion in the synthetic gas main pipeline. Hubei Yihua Chemical Co., Ltd.: gasification process; June 2007 – 4 people suffered minor injuries, including 1 person who suffered burns. A gas leak occurred at the top of the heat exchanger in the synthetic ammonia No. 1 system, and the leaking gas exploded due to friction, triggering a fire. Shandong Deqilong Chemical Group Co., Ltd. – Gasification process: In July 2007, 9 people died and 1 was injured; the company was on the verge of bankruptcy and was reorganized by Yankuang. Serious issues existed with the seventh-stage outlet pipeline of Compressor No. 2, including insufficient strength, poor welding quality, and no pressure testing before the pipeline was put into use, which led to an explosion in the outlet pipeline and a fire caused by the gas leak. Henan Coal and Chemical Industry Group’s Zhongyuan Dahuahua Company – Gasification process (Shell): In February 2008, 3 people died and 1 was injured. The connecting solenoid valve of the nitrogen tank malfunctioned, allowing nitrogen to enter the ash filter; this caused the workers carrying out rust removal tasks to suffocate and faint. Blind attempts at rescue led to an increase in casualties. Guizhou Xinghua Chemical Co., Ltd. – Gasification process; August 2008: 3 deaths, 2 injuries. An explosion and fire occurred in the methanol storage area of Guizhou Xinghua Chemical Co., Ltd. There were 8 methanol storage tanks in that area, and the accident resulted in damage to 6 of them (3 tanks with a capacity of 1000 cubic meters each and 3 tanks with a capacity of 250 cubic meters each). 3 people died and 2 were injured

I hope experts can share some detailed case analyses. Thank you!